I. Field and Purview
The present invention concerns a multi-hooded enarthrodial joint implant cup, which has a securing member; such cup ensemble in conjunction with a ball-containing counterpart joint implant component; and the securing member. The same can be for a hip.
II. Art and Problems
Dislocation of hip implants is a serious problem. Frequently the dislocation is debilitating to the patient, and can require a further surgery or implant to attempt to correct the problem.
In addressing this problem, various art is known.
U.S. Pat. No. 6,299,647 to Charles O. Townley discloses a snap-fitting, non-dislocating hip joint socket implant. This has a snap-fitted arrangement of the head-restraining marginal outlet of the acetabular component with posterior and anterior cut outs of the implant to avoid premature impingement against a prosthetic femoral neck, and a hood that is a marginally extended continuation of the superior one-half or so of the cup containment that is of a sufficient magnitude to reduce the overall dimension of the socket outlet to less than a hemisphere.
Sometime about 1997, William Harris discussed at Harvard University a double-hooded acetabular cup. This had opposing hoods that reduced the dimension of the socket outlet to less than a hemisphere. In conjunction with this cup, a certain retaining ring was also provided. Such a system is marketed by Zimmer, Inc. Compare, Zimmer, Inc., Epsilon™ Durasul (Reg. U.S. Pat. & Tm. Off.) Constrained Insert, Product Information and Surgical Technique.
Such art has its drawbacks. Dislocation still can and does occur, even with the known double hooded acetabular cups, and even the system with the ring mentioned above.
It would be desirable to improve the art. In particular, it would be desirable to provide an acetabular cup that is more resistant to dislocation.